conditioning system utilizing



June 1, 1943. r R. T. PALMER 2,320,973

AIR CONDITIONING SYSTEM UTILIZING REFRIGERATION Filed June 21, 1940 INVENTORI I 1 Patented June 1, 1943 AIR CONDITIONING SYSTEM UTILIZING REFRIGERATION Robert T. Palmer, Sharon, Mass, asslgnor to B. F. Sturtevant Company, Boston, Mass.

Application June 21, 1940, Serial No. 341,601

3 Claims.

This invention relates to air conditioning systems and relates more particularly to air cooling systems for passenger vehicles.

It has been found possible to cool the passenger space in railway passenger cars, during considerable periods of time in summer, by the circulation of large volumes of outdoor air through the car. At times however, during high outdoor temperatures, thisdoes not provide sufficient cooling, so it is desirable to provide refrigeration to supplement the pressure ventilation during high temperature periods.

The most satisfactory method of cooling the Y passenger space of railway passenger cars by pressure ventilation is to place a plurality of centrifugal fans along the longitudinal centers of the cars, with the fan wheels below the cellings and communicating through the ceilings with outdoor air. This invention provides an auxiliary refrigerative cooling system particularly suitable for use with.fans so placed.

In one embodiment of the invention, a zig-zag partition above the ceiling divides the centrifugal fans into two groups. Both groups communicate with outdoor air and are operated to supply 100% outdoor air during the pressure ventilating cycles. One group communicates with air from the passenger space for recirculation. For temperatures below a predetermined maximum with all fans operating, the car thermostat operates controls to disconnect the refrigeration and to prevent the supply of recirculated air to the fans. For temperatures above the predetermined maximum, the car thermostat acts to disconnect one group of fans, to adjust a damper to admitrecirculated air to the other group of fans, and to start the supply of refrigeration.

mounted with their motors above and their wheels below the ceiling i of the car. The details of the fans 5 and their mountings are shown by the U. S. Patent No. 2,142,834, which issued January 3, 1939, on an application of C. O. Bergstrom.

The zig-zag partition I which extends vertically between the ceiling 6 and roof 8 of the car divides the space between the ceiling and roof into two passages 9 and Ill, and the fans 5 into two groups, one group in the passage 9 and the other group in the passage ill. a

The passage l0 connects with the outdoor air inlet II in one end of the car in one of the car vestibules. The passage 9 connects with the evaporator unit, I! in the other end of the car. The unit I2 connects with the air passage 13 leading to the outdoor inlet M in the other vestibule of the car.

The recirculated air inlet l5 connects through the air passage IS with the air passage l3. The

damper I1 is adjustable in one position to close off the recirculated air passage l6 and in another position to open the passage l6 and to damper the system will be explained.

An'object oi the invention is to reduce the cost of air conditioning systems.

Another object of the invention is to supply a cooling effect through the circulation of large volumes of outdoor air and to use refrigeration only when the circulation of the large volumes of outdoor air is not efiective.

The invention will now be described with reference to the drawing, of which:

Fig. 3. is a schematic plan view illustrating an embodiment of this invention in a railway passenger car; r

Fig. 2 is a schematic elevation view of the car of Fig. l, and

Fig. 3 is a diagrammaticview oi the apparatus used and of the controls therefor.

As illustrated by Figs. 1 and 2, the railway passenger car contains the six centrifugal fans 5 oitdoor air through the inlet [4 to 25% capacity.

Referring now to Fig. 3, the operation of the The thermostat it, which may be an indoor or outdoor thermostat, converts the system tooperate in a pressure ventilating cycle when the temperature of the outdoor air is not too high for it to be effective.

If the temperature of the outdoor air is above say 80 F., the thermostat it closes an electric circuit including the motor I9 driving the compressor 20, and the electric source 23. This. causes the compressor 29 to supply a refrigerant through the condenser 25 and expansion valve 22 to the evaporator it. At the same time, the thermostat it opens the electric circuit including the motors 26 which drive the fans in the passage lt causing these fans to shut down. At the same time the thermostat opens the electric circuit including the damper motor 25 causing it to adjustthe damper H for partial recirculation so as to admit 75% recirculated air from the pas sage it into the passage l3 and 25% outdoor air from the inlet i i, into the passage l3. The motors driving the fans 5 in the passage 9 continue in operation and draw the mixed air through the evaporator and supply it into the passenger space.

Thus when the thermostat is actuated to call for cooling, it shuts down half the fans and.

actuates a damper to greatly decrease the volume of outdoor air and to admit a relatively large volume of recirculated air, and turns on the compressor to supply refrigeration. I

When the outdoor temperature is low enough for pressure ventilation to be suilicient, the thermostat l8 opens the circuit of the compressor motor l9 to shut down the compressor, and closes the energizing circuits of the fan motors 24 and the damper motor. The damper I1 is then adjusted to fully close the recirculated air passage l6 and to fully open the outdoor air inlet 14. All fans operate to supply large volumes of 100% outdoor air.

While one embodiment of the invention has been described for the purpose of illustration, it should be understood that the invention is not limited to the exact apparatus and arrangement of apparatus illustrated, since departures therefrom may be suggested by those skilled in the art without departure from the essence of the invention.

What is claimed is:

1. An air conditioning system for a passenger vehicle, comprising a plurality of fans spaced longitudinally of the vehicle, means including a partition extending longitudinally of said vehicle dividing said fans into two groups, an air cooler connected to one of said groups, a recirculated air passage and an outdoor air passage connected to said cooler, an outdoor air passage connected to the other of said groups, refrigeration supply means for said cooler, and means including a thermostat for deenergizing the fans of said other of said groups and for energizing said supply means and for throttling the supply of outdoor air through said first mentioned outdoor air passage and for admitting air from said recirculated air passage into said cooler.

2. An air conditioning system for a passenger vehicle, comprising a plurality of fans spaced along the longitudinal center of the vehicle. means including a zig-zag partition dividing said fans into two groups, an air cooler connected to one of said groups, a recirculated air passage and an outdoor air passage connected to said cooler, an outdoor air passage connected to the other 01' said groups, refrigeration supply means for said cooler, and means including a thermostat for do: energizing the fans of said other 01' said groups and for energizing said supply means and for throttling the supply of outdoorairthrough said first mentioned outdoor air passage and for admitting air from said recirculated air passage into said cooler.

3. An air conditioning system for a passenger vehicle, comprising a plurality of fans spaced along the longitudinal center of the vehicle, means including a zig-zag partition dividing said fans into two groups, an air cooler connected to one of said groups, an outdoor air passage connected to said cooler, an outdoor air passage connected to the other of said groups, refrigeration supply means for said cooler, and means including a thermostat for deenergizing the fans of said other of said groups and for energizing said supply means and for throttling the supply of outdoor air through said first mentioned outdoor air passage.

ROBERT T. PALMER. 

